On Friday, 1 November 2013, at around 02:13hrs, an explosion took place at the Riverhead branch of the Barclays Bank in Sevenoaks, Kent.

Officers from Kent Police attended after they were alerted that the bank's security systems had been breached.

When they arrived they found the ATM machine attached the front of the bank had been severely damaged and the bank had been entered. On further inspection it was ascertained that two cash cassettes containing £19,000 had been stolen and the building had suffered structural damage.

An investigation was launched and CCTV seized from the bank. The footage revealed a number of men placing tools around the premises before gas canisters are attached to the ATM machine and used to cause an explosion.

A hooded man then smashed his way into the bank with a sledgehammer; he was quickly followed by a second man wearing a baseball cap.

The incident lasted around 20 minutes in total before the men made off in a 3 Series BMW Estate.

In mid November detectives from the Met's Flying Squad began working alongside Kent detectives to identify and arrest the gang responsible for the attack on the bank.

A proactive operation code named Op Amplum was launched.

On Thursday, 21 November 2013, staff at the Borough Green, Kent branch of Barclays Bank noticed that the ATM machine wasn't working so they checked branch CCTV. During review of the footage they found that two men were captured at around 02:22hrs tampering with the machine and appear to be poking a large hose which is connected to a gas canister. This incident was linked by methodology to the robbery on 1 November.

Enquiries into Spinks' movements found that during October he was in contact with a number of companies that supply gas cylinders for legitimate purposes; these were the same type used to cause the explosion on 1 November 2013.

Proactive enquiries officers also established that Spinks and Smith travelled together during November when they purchased head torches and Velcro straps which were also the same kind used in the offence on 21 November 2013.

Lee Spinks was arrested by officers from the Flying Squad on 11 November 2013. He made no comment to all questions put to him. He was charged and remanded in custody.

On Thursday, 28 November 2013 at 02:35hrs, detectives from the flying squad observed a Nissan Note and an Audi A3 entering Borough Green in Kent. The Audi pulled off the main road and began roaming the approach roads to the village while the Nissan went to the village branch of Barclay's.

Gary Smith and Luke Cassidy who were wearing balaclavas, head torches and carrying gas canisters were observed walking towards the bank. At this point they were arrested by detectives from the Flying Squad.

Various paraphernalia was found placed outside the bank including a sledgehammer, a wrecking bar and gas canisters.

Danny Smith was arrested shortly afterwards driving the Nissan. He was found to be wearing one latex glove and one fabric glove.

Detective Inspector Mark Bedford Met's Flying Squad, said: "This was an organised group of criminals who used an elaborate method to steal money from the bank. However the Flying Squad worked alongside our Kent colleagues to mount a quick-time proactive operation to identify and arrest them. I am confident that today's guilty pleas are due to the quality of the evidence built up against them. I would like to thank all the officers involved in this investigation from the MPS and Kent who worked around the clock to bring to a swift conclusion the activities of a dangerous criminal gang.